Belt grinding and polishing machine



Aug. 15, 1967 s. BADER BELT GRINDING AND POLISHING MACHINE 2 Sheets-Sheet 1 Filed June 17, 1964 INVENTOR JTEPHENEADE/E. BY

4 TO/PIVEK).

Aug. 15, 1967 s. BADER BELT GRINDING AND POLISHING MACHINE 2 Sheets-Sheet 2 Filed June 17, 1964 INVENTOR.

477' ENE/91 ted States atent O 3,335,528 BELT GRINDING AND PULISHING MACHINE Stephen Baden, Valley Falls, N.Y. 12185 Filed June 17, 1964, Ser. No. 375,747 Claims. (Cl. 51-148) This invention relates to grinding and polishing machines and particularly to a machine of this type employing an endless belt.

The present invention concerns improvements in the belt grinding machine described in my United States Patents Nos. 2,578,662 and 2,763,103, and provides several advantages over both of these patents.

Belt grinding and polishing machines embodying the present concept are particularly adapted among other possible uses for, use on auto bodies, the inside of milk tanks, forming dyes, railings, patterns and any hard to reach surface, for example.

A feature of this invention is to provide a new and improved belt grinding and polishing machine which may be readily carried about and used by hand, and which may be mounted on numerous tools such as work benches, milling machines, lathes or boring mills, for example.

The belt grinding and polishing machine of the invention is of extremely compact construction and assembly and overall lightness in Weight, encased in a housing of such small dimensions as to occupy only a small portion of a work bench or table, and being easily portable, and in fact the first portable unit operating upon the above basic principles that has thus far been produced. This is particularly important because an operator can continue Working for longer periods of time without excessive fatigue.

Another feature of the present invention resides in the provision of a new and improved belt grinding and polishing machine which contains less obstructions to hinder the operator when grinding or polishing hard to reach places, which is adaptable to reach inside corners as well as flat surfaces, which is adaptable for use on metal, woodworking or other materials, which can utilize cloth or rubber rollers of varying diameters that are adaptable to shape themselves to any surface to be sanded or polished, which can employ concave or convex shaped wheels with different types of surfaces for different purposes as desired, which can have various degrees of abrasiveness in different belts and which can readily employ belts of varying lengths, with which the endless belt may be rapidly replaced, and which does not produce circular grain marks on the work product.

Moreover, another feature of this invention is to provide a new and improved belt sanding and polishing machine which can be operated by relatively unskilled operators, which requires minimum adjustment for operating, which provides a simple method of changing the belt, which automatically provides a predetermined tensioning of the belt, which provides means for guarding the operators hand from the rapidly moving belt, which provides means for protecting the operators hand in the event the belt breaks or partially ruptures, and which provides means for limiting the pivotal movement of the belt tensioning means in the event that the belt breaks during operation.

In essence, the present invention contemplates the provision of a belt sanding and polishing machine compris ing a mounting member which has an inner portion and an outer portion. The outer portion is swivelly connected to and supported by the inner portion and in turn supports a contact roller mounted thereon. A drive roller is mounted on and carried by the inner portion. A second mounting member is pivotally connected to the inner portion and a roller mounted thereon. An endless belt memice her is adapted to engage the outside surface of the aforementioned three rollers. A resilient shield member is anchored at one end to the inner portion and fn'ctionally engages the second mounting member at the other end to cause tensioning of the belt member.

According to one form of the present invention, a backing plate is mounted on the mounting member having an outside surface to support an endless abrasive belt against the counterforce of an engaging work piece.

According to another form of this invention, the belt is adapted to engage and drive a hub carrying an enlarged side bufling head for purposes of polishing the Work piece.

Other features, objects and advantages will be apparent from the following description of several embodiments of the invention, and the novel features will be particularly pointed out hereinafter in connection with the appended claims.

In the accompanying drawings:

FIG. 1 is a side elevation showing the belt grinding and polishing machine constructed in accordance with the concepts of this invention;

FIG. 2 is a plan view of the machine shown in FIG. 1;

FIG. 3 is an enlarged fragmentary view showing another method of interconnecting the second mounting member with respect to the inner portion of the first mounting member;

FIG. 4 is a fragmentary side elevation of a second embodiment of the belt sanding machine;

FIG. 5 is an enlarged fragmentary view showing alternate mounting means for the contact roller;

FIG. 6 is a side elevation of the contact roller of FIG. 5;

FIG. 7 is an enlarged fragmentary view showing a buffing wheel mounted on the outer portion of the driven mounting member;

FIG. 8 is a fragmentary side elevation view showing a backing plate and means for mounting thereof; and

FIG. 9 is a sectional view taken along the line 99 of FIG. 8. v

In the embodiment of the invention illustrated in FIGS. 1 and 2, the belt sander includes a mounting member 10 having an outer portion 12 and an inner portion 14, the outer portion 12 being swivelly connected to and supported by the inner portion as by means of pivot pin 16. An adjusting screw 18 having a finger actuated rotating knob 20 engages the outer portion 12 as at 22 and threadedly engages the inner portion as at 24 for purposes of aligning the outer portion 12 With respect to the inner portion 14. A work engaging or contact roller 26 is rotatably carried by shaft 28 which is positioned in boring 30 in the outer portion 12 and secured by a nut 32. It Will be appreciated that the outside surface of the contact roller 26 is adapted to support an endless abrasive belt 34 against the counterforce of an engaging work piece. It is also to be pointed out that contact wheel 26 may have an exterior surface of one of many different materials of relative differing hardnesses including a cloth wheel for purposes of flattening under pressure to give a large smooth finishing area. Moreover, the contact wheel 26 may assume varying shapes ranging from a relatively wide Wheel to a relatively narrow or tapered contour. Thus, it is seen that this machine is readily adapted to engage irregular or angularly shaped surfaces.

As best seen in FIGS. 1 and 2, the inner portion 14 of the mounting member 10 is provided with mating extensible members 36 and 38, member 36 being substantially a hollow square frame as viewed in cross section (FIG. 9) and member 38 being of substantially the same configuration but of smaller size to slidably engage the inside of member 36 in a telescopic manner. Member 36 is provided with an elongated slot 40 (FIGS. 1 and 9) and member 38 is provided with a threaded hole 42 (FIGS. 2

and 9) for receiving an adjusting screw 44 having a top portion 46. In order to adjust the length of the mounting member 10, the adjusting screw 44 is loosened and the member 38 is slid inwardly or outwardly as desired, then adjusting screw 44 is tightened until the knob portion 46 frictionally engages the member 36 and thereby holds the mounting member at its selected length.

Inner portion 14 is also provided with a hand grip 48 (FIGS. 1 and 2) which the operator may readily grasp while operating the machine.

As best seen in FIG. 2, the inner portion 14 is provided With an air motor 50 mounted on the side thereof as at 52. The air motor 50 is provided with an air hose connection 54 of standard construction well known in the trade. A drive shaft 56 (FIG. 1) extends from the air motor 50 and a drive roller 60 is keyed thereto as at 58. The endless belt 34 is supported and driven by the outside surface of the drive roller 60.

The inner portion 14 is further provided with an annular groove 62 which extends from a first location 64 (FIG. 1) to a second location 66 (FIG. 1) and is further disposed between the drive roller and the air motor. A second mounting member or mounting plate 68 is concentrically mounted about shaft 56 within the annular groove 62. The mounting plate 68 is provided with raised portions 70 and 72 (FIGS. 2 and 3) which limit the amount of rotational travel of the mounting plate 68. Consequently, when the mounting plate is rotated in a counterclockwise direction as viewed in FIG. 1 and FIG. 3 the raised portion 72 strikes the base of the annular groove 62 at location 66. Conversely, when the mounting plate 68 is rotated in a clockwise direction from the position shown by the solid lines in FIG. 3 to the position shown by the dotted lines in FIG. 3, the raised portion 70 of the mounting plate 68 engages the base of the annular groove 62 as at location 64, and thereby limits the amount of clockwise rotational travel of the mounting plate 68.

Still referring to FIG. 1, roller 74 is rotatably mounted on shaft 76 which is affixed to mounting plate 68, and the endless belt member 34 is adapted to engage the outside surface thereof.

A pair of pins 78 and 80 (FIG. 1) are fixedly connected to the hand grip 48 of the inner portion 14, and a pin 82 is fixedly connected towards the outer portion of the mounting plate 68. A resilient safety guard member 84 is anchored at one end by being partially passed around pin 78 and frictionally engaging pin 80, and the other end thereof is adapted to frictionally engage pin 82 as shown in FIG. 1. As seen in FIGS. 1 and 2, the resilient safety guard member 84 is disposed between the hand grip 48 and the moving belt 34 and hence acts as an effective guard protecting the operator. It is particularly noted that in the event that the belt 34 should break the loose end portions thereof would not slap around and hit the operators hand while gripping the hand grip 48.

Further, it will be appreciated that the resilient safety guard 84 exerts a force against the pin 82 tending to rotate the mounting plate 68 in a counterclockwise direction as viewed in FIG. 1, and thereby increasing the linear distance between the roller 74 and the roller 26, and accordingly increasing the tension force in the belt 34, proportionately.

Still referring to FIG. 1, resilient safety guard 84 is provided with an upper lip or hook portion 86 which serves as an alternative method of preventing excessive clockwise rotation of the mounting plate 68 as viewed in FIG. 1. After rotating through a predetermined arcuate distance in a clockwise direction as viewed in FIG. 1, the mounting plate 68 is prevented from further rotation by the hook portion 86 engaging the pin 32.

In operation the belt member 34 is loosely positioned about the rollers 26, 60 and 74 and a rough adjustment of the linear distance between the rollers is obtained by adjusting the length of the mounting member 10 by means of the adjusting screw 44. FIG. 1 shows the mounting member 10 in its elongated or extended position whereas FIG. 4 shows the member 10 in its shortened or retracted position. Final tensioning of the belt 34 is achieved by means of the resilient safety guard 84 which tends to rotate the mounting plate 68. It is noted that the tension thus obtained in the belt 34 is substantially a function of the resiliency of the safety guard 84 rather than the arbitrary discretion of the operation, and hence less skill is required by the operator. Further, attention is directed to the fact that tension is maintained on the belt 34 even though the diameter of the contact roller 26 is constantly changing during operation of the machine because of variance in the counterforce of an engaging work piece. In the event that the inner portion 14 is not in proper alignment with the outer portion 12 of the mounting member 10, the belt 34 will tend to slip off the rollers. Proper alignment is readily obtained by means of the adjusting screw 18 as described more fully in my aforementioned patents.

Referring now to FIGS. 4, 5 and 6, the belt grinding and polishing machine is provided with a contact roller 88 which is of smaller diameter and greater width than contact roller 26 of FIGS. 1 and 2. The roller 88 is rotatably mounted on shaft 90 which is threadedly connected to the outer portion 12. Grooves 94 (FIG. 6) may be provided on the outside surface of the contact roller 88 for purposes of better supporting the endless abrasive belt against the counterforce of certain engaging work pieces.

FIG. 7 shows still another embodiment of the invention wherein belt 34 is adapted to engage and drive hub 96 carrying an enlarged side bufiing head 98 for purposes of bufiing or polishing the work product. The buffing attachment designated generally at is rotatably mounted on shaft 100 which passes through boring 30 of the outer portion 12 and secured thereto by means of nut 32.

Referring to the embodiment of the invention shown in FIGS. 8 and 9, the belt sander further comprises a backing plate 101 having an outside surface to support an endless abrasive belt 34 against the counterforce of an engaging work piece having a substantially flat surface configuration. Member 38 is provided with a threaded hole 102 for receiving a clamp bolt 104 (FIG. 8). The backing plate 101 has a pair of depending backing plate brackets 108 and 110 and is adjustably connected to the mounting member 10 by means of adjusting screw 44 and clamp bolt 104 which pass through 112 and 114 in the brackets 108 and 110, respectively. That is, the relative positioning of the backing plate 101 with respect to the mounting member 10 is accomplished by loosening adjusting screw 44 and clamping bolt 104, sliding the plate in the slots 112 and 114 as desired, and thence tightening the adjusting screw 44 and clamping bolt 104.

It will be understood that various changes in the details, materials and arrangements of parts which have been hereindescribed and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. A belt sander comprising a mounting member having an inner portion and an outer portion, said outer portion being connected to and supported by said inner portion, a contact roller mounted on and supported by said outer portion, a drive roller mounted on and carried by said inner portion; a second mounting member pivotally connected to said inner portion, a roller mounted on and supported by said second mounting member, the outer surfaces of said rollers being adapted to support an endless belt thereagainst, and a plate-like resilient shield member anchored at one end to said inner portion and engaging said second mounting member at the other end to cause tensioning of said belt member, said shield member being disposed between the endless belt and an operator when in normal operating position.

2. A belt sander comprising a mounting member having an inner portion and an outer portion, said outer portion being connected to said inner portion, a contact roller mounted on and supported by said outer portion, a drive roller mounted on and carried by said inner portion; a second mounting member pivotally connected to said inner portion, said second member being adapted to pivot about the axis of said drive roller, and a plate-like resilient shield member fixedly connected at one end to said inner portion and adapted to engage said second mounting member at the other end thereof to urge rotational movement of the second mounting member, said shield member being disposed between the second member and an operator when in normal operating position.

3. A belt sander comprising a mounting member having an inner and an outer portion, a contact roller having an outside surface to support an endless abrasive belt against the counterforce of an engaging work piece, said contact roller being mounted on said outer portion, a drive roller mounted on said inner portion, motive means for said drive roller mounted on said inner portion adjacent said drive roller, a second mounting member pivotally connected to said inner portion adjacent said motive means, a roller mounted on and supported by said second mounting member, and a plate-like resilient shield member fixedly connected at one end to said inner portion and resiliently engaging said second mounting member at the other end to cause pivotal movement of said second mounting member, said shield member being disposed between the endless belt and an operator when in normal operating position.

4. A belt sander comprising a mounting member having an inner portion and an outer portion, a contact roller mounted on and supported by said outer portion, a drive roller mounted on and carried by said inner portion; a second mounting member pivotally connected to said inner portion, a roller mounted on and supported by said second mounting member, the outer surfaces of said rollers being adapted to support an endless belt thereagainst, said inner portion being supplied with a hand grip section, a resilient shield member anchored at one end to said inner portion and engaging said second mounting member at the other end to cause rotational movement of said second member, said resilient shield member being of suflicient width and disposed between said hand grip and said belt member whereby an operators hand is protected.

5. A belt sander comprising a mounting member having an inner portion and an outer portion, said outer portion being swivelly connected to and supported by said inner portion, a contact roller mounted on and supported by said outer portion, said roller comprising a hub portion having an outside surface to support an endless belt, and a buifing portion having an outside surface adapted to engage a work piece, a drive roller mounted on and carried by said inner portion, a second mounting member pivotally connected to said inner portion, a roller mounted on and supported by said second mounting member, and a platelike resilient shield member anchored at one end to said inner portion and engaging said second mounting member at the other end to cause tensioning of said belt member, said shield member being disposed between the endless belt and an operator when in normal operating position.

6. A belt sander comprising a mounting member having an inner portion and an outer portion, said outer portion being swivelly connected to and supported by said inner portion, a roller mounted on and supported by said outer portion, a drive roller mounted on and carried by said inner portion; a second mounting member pivotally connected to said inner portion, said rollers having outside surfaces to support an endless abrasive belt, a plate-like resilient shield member anchored at one end to said inner portion and engaging said second mounting member at the other end to cause tensioning of said belt member, said shield member being disposed between the endless belt and an operator when in normal operating position, a backing plate adjustably mounted on said first mounting member, and said backing plate having an outside surface to support said endless abrasive belt against the counterforce of an engaging workpiece.

7. An endless abrasive belt polishing and grinding machine comprising a mounting member having an inner portion and an outerportion, said outer portion being swivelly connected to and supported by said inner portion, a contact roller mounted on and supported by said outer portion, a drive roller mounted on and carried by said inner portion, means for adjusting the relative position of said drive roller and said contact roller one with respect to the other; a second mounting member pivotally connected to said inner portion, a roller mounted on and supported by said second mounting member, a hand grip mounted on said inner portion, a resilient shield member anchored at one end to said inner portion and frictionally engaging said second mounting member at the other end thereof to cause rotational movement of said second mounting member, and said resilient shield member being of sufiicient width and disposed between said hand grip and said drive roller thereby protecting an operators hand.

8. An endless abrasive belt polishing and grinding machine comprising a mounting member having an inner portion and an outer portion, means for adjusting the linear alignment of said outer portion with respect to said inner portion, a contact roller mounted on and supported by said outer portion, a drive roller mounted on and carried by said inner portion; a second mounting member pivotally connected to said inner portion, a roller mounted on said second mounting member, the outside surfaces of said rollers being adapted to support an endless abrasive belt, a resilient shield member, pin means for anchoring one end of said shield member to said inner portion, a pin mounted on said second mounting member, the other end of said shield member being adapted to frictionally engage said pin, said shield member being provided with a lip at the free end thereof for engaging said pin to limit the rotational travel of said second mounting member.

9. A belt sander comprising a mounting member having an inner portion and an outer portion, a contact roller mounted on and carried by said outer portion, a drive roller mounted on and carried by said inner portion, said inner portion being provided with an annular groove concentrically disposed with respect to the center of said drive roller and extending an arcuate distance between a first location and a second location, a second mounting member pivotally connected to said inner portion and adapted to rotate within said annular groove, said second mounting member being provided with a first and second raised portion arcuately spaced one from the other and adapted to engage the base of the annular groove at said first and second locations respectively to limit the rotational movement of said second mounting member, a roller mounted on and supported by said second mounting member, the surfaces of said rollers being adapted to receive an endless belt member, a resilient shield member anchored at one end to said inner portion and frictionally engaging said second mounting member at the other end thereof to cause rotational movement of said second mounting member.

10. A belt sander comprising a mounting member having an inner portion and an outer portion, said outer portion being swivelly connected to and supported by said inner portion, means for adjusting the linear alignment of said outer portion with respect to said inner portion, a contact roller mounted on and supported by said outer portion, a drive roller mounted on and carried by said inner portion, motive means for said drive roller mounted a on said inner portion adjacent said drive roller, said inner portion having a hand grip disposed adjacent said drive roller; said inner portion being provided with an annular groove concentrically disposed with respect to the center of said drive roller and extending an arcuate distance between a first location and a second location, a second mounting member pivotally connected to said inner portion and adapted to rotate within said annular groove, said second mounting member being provided with a raised portion which is adapted to engage the face of the annular groove at said first location to limit the rotational movement of said second mounting member in one direction, a roller mounted on and supported by said second mounting member, the surfaces of said rollers being adapted to receive an endless abrasive belt, a resilient shield member, pin means for anchoring one end of said shield member to said inner portion, a pin mounted on said second mounting member, the other end of said shield member being adapted to frictionally engage said pin, said shield member being provided with a lip at the free end thereof for engaging said pin to limit the rotational travel of said second mounting mem- References Cited UNITED STATES PATENTS 1,773,077 8/1930 Newman. 2,624,160 1/1953 Harper 51-141 2,763,103 9/1956 Bader 51-135 3,049,841 8/1962 Guinn 51l70 FOREIGN PATENTS 269,695 1/ 1914 Germany.

ROBERT C. RIORDON, Primary Examiner.

D. G. KELLY, Assistant Examiner. 

1. A BELT SANDER COMPRISING A MOUNTING MEMBER HAVING AN INNER PORTION AND AN OUTER PORTION, SAID OUTER PORTION BEING CONNECTED TO AND SUPPORTED BY SAID INNER PORTION, A CONTACT ROLLER MOUNTED ON AND SUPPORTED BY SAID OUTER PORTION, A DRIVE ROLLER MOUNTED ON AND CARRIED BY SAID INNER PORTION; A SECOND MOUNTING MEMBER PIVOTALLY CONNECTED TO SAID INNER PORTION, A ROLLER MOUNTED ON AND SUPPORTED BY SAID SECOND MOUNTING MEMBER, THE OUTER SURFACES OF SAID ROLLERS BEING ADAPTED TO SUPPORT AN ENDLESS BELT THEREAGAINST, AND A PLATE-LIKE RESILIENT SHIELD MEMBER ANCHORED AT ONE END TO SAID INNER PORTION AND ENGAGING SAID SECOND MOUNTING MEMBER AT THE OTHER END TO CAUSE TENSIONING OF SAID BELT MEMBER, SAID SHIELD MEMBER BEING DISPOSED BETWEEN THE ENDLESS BELT AND AN OPERATOR WHEN IN NORMAL OPERATING POSITION. 